This package is not actively maintained. If you would like to get involved please let me know
This python interface (formerly oecpy) serves as a link between the raw XML of the Open Exoplanet Catalogue. It allows:
- Searching of planets (including alternate names)
- Easy reference of planet parameters ie GJ1214b.ra, GJ1214b.T, GJ1214b.R
- Calculation of values like the transit duration.
- Define planet types and query planets to find out what they are
- Easy rescale of units
- Easily navigate hierarchy (ie from planet to star or star to planets)
- Availability of system parameters in planets (ie ra, dec, d (distance))
If you use ExoData in a scientific publication, please include a reference to this paper http://dx.doi.org/10.1016/j.cpc.2016.05.009.
Full documentation is currently being built here. For now this page and the ExoData paper are the best sources.
This module depends on
- Quantities
- numpy
- nose
- matplotlib
- requests
- hypothesis
- Open Exoplanet Catalogue (somewhere on your system)
Currently only tested under Python 2.7, 3.4, 3.5 on mac and linux. If you use windows or a different python version try it anyway and open an issue if you encounter problems.
Easiest way
pip install exodata
Or from this repo
python setup.py install
You can either download and manage the Open Exoplanet Catalogue yourself or automatically load the latest version from the web each time.
To get your own copy move to the folder on your system where you want to store it and clone the Open Exoplanet Catalogue (this process will create a folder named open-exoplanet-catalogue within your working directory).
git clone https://github.com/OpenExoplanetCatalogue/open_exoplanet_catalogue.git
The catalogue should then download. If you want to update the catalogue, move to the open_exoplanet_catalogue folder and pull
cd open_exoplanet_catalogue/
git pull origin master
If you want to keep track of this repo in a GUI way, I recommend sourcetree or the github client.
This section was generated using the OEC version dc8c08a4ba0c64dd039e96c801d12f17c82a7ff3 (1st May 2016)
import exodata
databaseLocation = '/git/open_exoplanet_catalogue/systems/' # Your path here (to systems folder)
exocat = exodata.OECDatabase(databaseLocation)
# To automatically load the latest version from github you can instead use load_db_from_url() which fetches
# the latest version from https://github.com/OpenExoplanetCatalogue/oec_gzip/raw/master/systems.xml.gz
exocat = exodata.load_db_from_url()
You can then access the lists
exocat.systems
exocat.stars
exocat.planets
exocat.transitingPlanets
The following code assumes the imports (along with loading exocat as above)
import exodata
import exodata.astroquantities as aq
You can now perform more advanced queries such as fetching all planets whose radius is less than 10 Earth Radii
>>> superEarths = [planet for planet in exocat.planets if planet.R < (10 * aq.R_e)]
>>> len(superEarths)
1096
To choose a planet
>>> kepler60b = exocat.searchPlanet('kepler60b')
>>> print kepler60b
Planet('Kepler-60 b')
>>> exocat.searchPlanet('kepler60') # or all the kepler 60 planets
[Planet('Kepler-60 c'), Planet('Kepler-60 b'), Planet('Kepler-60 d')]
>>> kepler60b.star # to get the star kepler-60
Star('Kepler-60')
>>> kepler60b.R # to get the planetary radius
array(0.196) * R_j # this works like an array in most functions
>>> kepler60b.R.rescale(aq.R_e) # See Units section for more
array(2.150770051797206) * R_e
>>> kepler60b.R.rescale(aq.m)
array(13702556.0) * m
>>> kepler60b.dec
<Latitude 42.265011111111114 deg>
>>> kepler60b.dec.dms # or in degrees, minutes and seconds
dms_tuple(d=42.0, m=15.0, s=54.040000000011901)
>>> gj1214b = exocat.searchPlanet('gj1214')
Planet('Gliese 1214 b')
>>> exocat.planetDict['Gliese 1214 b'] # or with the exact name
Planet('Gliese 1214 b')
For a full list of planets, star and system parameters see Appendix B (pg 16-19) of the ExoData paper.
units are handled by the quantities package
import quantities as pq
You can then access most units and constants such as meters pq.m, astronomical units pq.au etc!
Some astronomy units such as R_e, R_j, R_s (where e is Earth, j is Jupiter and s in the Sun) are not included (yet) in quantities so you need to refer to them as aq.R_e by importing exodata.astroquantities
import exodata.astroquantities as aq
exodata.astroquantities includes all pq units so only the aq import is necessary
There are also other units such as mass (M_e, M_s and M_j).
You can read more about the Quantities package here.
The equations module contains many exolanet equations that be be used independantly or called directly from a planet or star object. Most equations are classes that when given all parameters bar one will calculate the missing one.
>>> from exodata.equations import KeplersThirdLaw
>>> KeplersThirdLaw(a=0.01488*aq.au, M_s=0.176*aq.M_s).P
array(1.579696141940911) * d
>>> KeplersThirdLaw(a=0.015*aq.au, P=1.58*aq.d).M_s
array(0.18022315673929148) * M_s
>>> gj1214b = exocat.planetDict['Gliese 1214 b']
>>> gj1214b.calcSurfaceGravity()
array(7.929735778087916) * m/s**2
>>> gj1214b.calcLogg()
2.8992587166958947
>>>> gj1214b.calcTransitDuration(circular=True)
array(52.74732533968579) * min
These are how a planet is classified acoridng to mass, radius and temperature along with assumptions for the albedo and mean molecular weight based on these parameters. Currently they are stored in the dictionary exodata.assumptions.planetAssumptions.
Overwriting these values (or adding new ones) will change the output. for example, looking at the mass types we can see a list defining the limits. Editing this list to change the values or add new classes will chnage how planet are classified in the program.
>>> exodata.assumptions.planetAssumptions['massType']
[(array(10.0) * M_e, 'Super-Earth'), (array(20.0) * M_e, 'Neptune'), (inf, 'Jupiter')]
A few options can be set within ExoData to change the global behaviour of the program. By default if a quantity is missing for a parameter it is calculated if possible. For example if you use .a for the semi-major axis and it is not present in the catalogue it will be calculated using the period and stellar mass and returned. This happens silently except for raising the Calculated SMA flag. (see flags). You can turn this behaviour off by typing
exodata.params.estimateMissingValues = False
This will only take scope in the current project so if you close the interpreter it will reset to True.
ExoData features a plotting library for planet and stellar parameters in a scatter plot and per parameter bin. Please see the plots section of the documentation for further information. Note that all plots are shown here were produced after import seaborn which changes the plot style.
Note if you want to replicate these plots in the default python interpretor you will need to import pyplot and issue the show command after each plotting code shown below. You will also need to close the open plot before typing any further commands.
import matplotlib.pyplot as plt
plt.show()
dm_plot = exodata.plots.DiscoveryMethodByYear(exocat.planets, methods_to_plot=('RV', 'transit', 'Other'))
dm_plot.plot(method_labels=('Radial Velocity', 'Transit Method', 'Other'))
exodata.plots.GeneralPlotter(exocat.planets, 'R', 'M', yaxislog=True).plot()
plt.xlim(0, 2.5)
exodata.plots.GeneralPlotter(exocat.planets, 'R', 'star.magV',
xunit=aq.R_e, xaxislog=True).plot()
exodata.plots.DataPerParameterBin(exocat.planets, 'e',
(0, 0, 0.05, 0.1, 0.2, 0.4, float('inf'))).plotBarChart(label_rotation=45)
You can also plot this as a pie chart
exodata.plots.DataPerParameterBin(exocat.planets, 'e',
(0, 0, 0.05, 0.1, 0.2, 0.4, float('inf'))).plotPieChart()
Plots can also be large (i.e. for presentations), and you can change the color easily with normal matplotlib syntax
exodata.plots.DataPerParameterBin(exocat.planets, 'M',
(0, 0.2, 0.5, 1, 2, 3, 6, 12, float('inf')), size='large').plotBarChart(c='r')
MIT License
Copyright (c) 2016 Ryan Varley
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.